Aim of this study was to assess quality of the Danube sediment from the water source "Ratno Ostrvo", which is in the vinicity of the Oil Refinery "Novi Sad" (Serbia, Yugoslavia), after bombardment of the refinery in 1999. In the period March-October 2000, sediment samples were analysed for their oil and oil-derivates contents, i.e. mineral oils contents, by quantitative IR-spectrophotometry, and by qualitative and quantitative GC/MS analyses for their polycyclic aromatic hydrocarbons (PAH) contents. Oil pollution was detected in sediment samples.

Drainage of industrial and communal effluents, directly into the water flow, as many hydrotechnical activities, significantly influence the schedule and balance of the processes that take place into water. In this paper, there are represented the results of systematic control of the water quality of the Danube river and DTD (Danube-Tisza-Danube) channel on the parts Vrbas-Bezdan and Becej-Bogojevo, at the control station network of the Republic Weather Bureau (the Republic of Serbia), for the period of 1991-1996. The results show that the most adverse influence of anthropogenic factor is on the part of the flow of the DTD (Danube-Tisza-Danube) channel from Vrbas to the flow into Tisza river.

Nowadays, different profile of experts are present opinion that surface water quality are exchanged. Type and degree of mineralization content exchange are shown by argumentation. The work have carried out taking into consideration suitability of Danube water for irrigation. The results of chemical investigation from three sample locations (Bezdan, Novi Sad and Banatska Palanka), Serbia (Yugoslavia) during the period 1981-1995, were analyzed. The main statistical parameters and tests of homogeneity are used during the work. Results have pointed put more or less concentration decreasing of analyzed parameters. From statistical point of view, exchange of electrical conductivity and potassium are prominent on all three localities.

The results of long standing and systematic monitoring of quality of river Danube's water, done by the net of stations for controllingquality of water of the Republic Hydrometeorological Service of Serbia (Yugoslavia) are given in this paper. The amount of organic matter (HPK, BPK5), concentration of dissolved oxygen, nutritive matters (NH4(+), NO2(-), NO3(-) and total PO4(3-) and conductivity are specially examined. The results are shown depending on seasonal measuring (average values for spring, summer, autumn and winter) during the period 1995-1998, and the changes are analyzed.

The paper presents the results of preliminary study of the intestinal content in bream (Abramis brama L. 1758) of the Danube River through the Belgrade Region. The fishes were collected in May and October during the period 2007-2009 at two sampling sites along the course. A total of 42 fish specimens of different age (2+ to 6+) were examined. By examination of compositing of intestine of bream have been found members from macrozoobentho-groups – Oligochaeta, Gastropoda (Lithoglyphus naticoides), Bivalvia, Amphipoda (Gamaridae). Our investigation showed that the diet of bream is dependent of bottom fauna composition and structure.

This paper presents the results of the Danube River water quality analysis based on the calculated SWQI index values, using the data set provided by the Hydrometeorological service of the Republic of Serbia for the year 2009. The relevant parameters are sampled once a month on average, at 16, measuring stations of the River Danube along the flow through Serbia. Data grouped on the sampling site basis, averaged on a yearly level, resulting in a median SWQI for each sampling station, are employed to obtain a synthesized quality indicator. Research shows that the overall quality of the water of the Danube in Serbia, SWQI = 85 for the given one-year period and to match the descriptive indicator very good water quality.

This paper presents the most important results on water quality investigation of the Danube river in the Iron Gate reservoir. The investigations are conducted by the Institute Jaroslav Cerni by means of regular monitoring renewed after a long pause in 2001. The determined phenomena are considered in regard to water quality of the Danube river in the upstream zone.

This paper provides an assessment of the Mlava River on the Danube River sediment quality. The contents of Zn, Cu, Pb, Cr, Ni, Cd and As were detected in the surface sediment. Based on the obtained concentrations of these seven metals sediment quality pollution category was determined with respect to PLI (pollution load index) and I geo (geo-accumulation index). It is found that M4 site, according to PLI and I geo (As and Cd) values can be classified as very highly polluted.

The aim of this study was to analyze nine heavy and trace elements (Zn, Fe, Al, As, Cu, Sr, B, Cd and Ba) of the three tissues (muscle, liver and gills) in sterlet (Acipenser ruthenus), black sea shad (Alosa immaculata) and barbel (Barbus barbus). All three species were sampled on the Danube (1173, 1319 and 863 rkm) in Serbia. The obtained concentations of heavy metals and trace elements were used for obtaining an overview of the presence of the abovementioned elements in a descending order and calculate the value of MPI (Pollution Metal index), which represents the total quantity of heavy metals and trace elements per tissue and species. In all the analyzed specimens iron (Fe) and zinc (Zn) were dominant, followed by strontium (Sr) and aluminum (Al), and the other trace elements and heavy metals. The least represented metals were barium (Ba) and cadmium (Cd). MPI values were the highest in liver, followed by gills and muscle of all species; with the exception of barbel, which had extremely high MPI values in the gills.